1. Field of the Invention
The invention relates to packet services in communication networks, and in particular, to the provisioning of quality of service levels for service sessions.
2. Description of the Prior Art
Recently, cable companies have begun to offer voice services in addition to the standard data and entertainment services of the past. The most common voice service offered is voice over packet (VoP), of which Voice over Internet Protocol (VoIP) is a well known example. Cable companies that offer multiple types of services are often times referred to as multi-system operators, or MSOs.
End users, such as residential and business customers, are accustomed to high levels of quality of service (QoS) from circuit switched voice providers, such as the local exchange carriers (LECs) that form portions of the public switched telephone network (PSTN). In order to compete with circuit switched voice providers, MSOs must be able to provide QoS at comparable levels.
FIG. 1 illustrates a communication network 100 in the prior art for providing QoS in a cable MSO network. Communication network 100 includes cable network 110, access system 105, destination system 120, end system 101, proxy system 112, and policy decision function (PDF) system 111. In communication network 110, cable network 110 provide transport for communications between access system 105 and destination system 120. Access system 105 provides end system 101 with access to cable network 110. End system 101 is typically connected to access system 105 by a hybrid fiber/coaxial connection (HFC). Cable network 110 is often times a high-speed Ethernet network, such as Gig-Ethernet. Proxy system 112 is typically a session initiation protocol (SIP) proxy system. Likewise, end system 101 could include a SIP end device. Proxy system 112 operates in accordance with well known protocols, such as SIP).
In operation, end system 101 registers with proxy system 112, including transmitting the network address of end system 101, such as its IP address, to proxy system 112. Proxy system 112 stores the current network address of end system 101 for later call processing.
FIG. 2 illustrates the operation of communication network 100 for provisioning QoS for a VoP session between end system 101 and destination system 120 in an example of the prior art. To begin, end system 101 transmits a SIP invite message to proxy system 112. The invite message indicates an identifier for end system 101 and a destination identifier for destination system 120. Proxy system 112 typically processes the invite message to perform call setup processes to setup a VoP call between end system 101 and destination system 120. As part of the call setup process, proxy system 112 transmits a QoS request to PDF system 111. The request indicates the network address for end system 101. In response, PDF system 111 looks up the requested QoS information and transmits the resulting QoS information to access system 105. Access system 105 configures the links between end system 101 and access system 105 in accordance with the QoS information. The appropriate QoS level is then applied to the VoP session between end system 101 and destination system 120.
One prior problem illustrated by FIG. 2 is that the current network address of end system 101 is required by PDF system 111 and access system 105 in the QoS provisioning process. In many cases, MSOs partner with third-party carriers to provide VoP services to the MSO customers. However, common boundary devices, such as session border controllers, block actual network addresses from passing across peered network borders. As a result, MSOs face increasing challenges in their attempts to provide high levels of QoS to customers who have become accustomed to the high QoS of the PSTN. In addition, carriers face increased challenges to their ability to provide QoS control over sessions originating from or terminating to a peered MSO network due to the presence of session border controllers.